NextPreviousHomeDynamic video differences in preview vs rendered movie

viddy | 12 years ago | 10 comments | 2,647 views

Hi Michiel,

I'm using dynamic content/xml files to display several videos inside a scene, so that each video reuses the same set of animations, one after the other.

The 'live' preview works perfectly, but when the movie is rendered, each dynamically loaded video after the first one seems to start playing earlier than the first frame of the scene, meaning the whole thing shifts out of sync throughout the rendered movie.

Any ideas?


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Wow, that is a VERY advanced setup. I'm impressed. Please give me some time to reproduce all this.

Which video format are you using?

michiel, 12 years ago

> "I'm impressed"

Don't be, Michiel - it's fairly simple (otherwise both cells in my brain would explode ;) )

> "Which video format are you using?"

Have tried compressed avi's (using Techsmith's screen capture codec), uncompressed, and wmv's.

Also at various fps output.

Have sent you an example setup with all files plus example render which shows what I mean... seems like the preview correctly initiates the next video from the xml file at the end of each show's run, whereas the render seems to start playing successive videos straight after the previous one has finished.


viddy, 12 years ago

The answer equals the answer I gave you to your previous question (Trigger video layer to play at a keyframe):

Videos always start playing at the beginning of the timeline.

As a consequence, when looping a show or using dynamic content with multiple entries, all videos play as if they've started from the absolute beginning of the show.

So the realtime 'live' behaviour is actually a bug.

Adding an option to make all videos restart at the beginning of each loop will help. But what if the next loop uses the same video? I think in that case you want the video to keep on playing. Things start to become complex when adding play and stop commands to the timeline (your previous questions) Should those commands always be performed? Or only used in the 1st loop? Ignored if the video hasn't changed?

For now, a simple workaround is to use videos that have the exact same duration as the BT show.

michiel, 12 years ago

The videos that you've sent me are in the FLV format. Which DirectShow filter are you using to play those files? Can you give me an URL?

If possible it would be great if you could write an article about playing Flash video files inside BT.

michiel, 12 years ago

Thanks for the answers, Michiel.

I personally really think if you can add something BASIC that covers this, you'll seriously rev up the abilities of this fantastic software...

...especially when using dynamic content is it saves one's most important asset: *time*...

Being able to set up a stage and reuse it several times over with different video content would fit in great with BF's aim of keeping things short, sweet, and ultra effective.

Currently, re-editing the video lengths defeats the object of using it for that purpose. So I hope there's some useful thoughts below...

"Things start to become complex when adding play and stop commands to the timeline (your previous questions)"

There's a potentially easier way round this where you don't need explicit start/stop commands on the timeline: you could tie it into a check on the video element's transparency:

* If the transparency < 1, start the video *

That way, you can set video clips to begin play at some point *during* the show, and still have the system work as it does now where a video can initiate from the *start* of the show (by having it off camera, or covered by another element for example).

With video, it's much easier to use a clip from its intended start position than to calculate the 'buffer' frames needed to add in relation to the show's length - especially as you'd need to edit that buffer for every timeline change you might make in tweaking things.

"But what if the next loop uses the same video? I think in that case you want the video to keep on playing."

I hadn't thought of that, but...

As using the xml files is more a advanced use of BluffTitler, I personally think it's ideal to just have an extra option or 2 that would allow for this (and it's all kept off the main interface).

There are 2 scenarios to consider (& probably at least a 3rd that my poor brain can't think of yet!)

Scenario 1:
If next video file is different, play from its starting frame

Scenario 2:
If next video filename is same, play from start
continue from end of last run

IDEA: If you added an optional flag to the XML, you might cover those options like this example:







Loop 1) test.avi plays (from its 1st frame)

Loop 2) test2.avi plays (from its 1st frame)

Loop 3) test2.avi plays (from its 1st frame)

Loop 4) test2.avi CONTINUES playing (from frame 'x')

Loop 5) test2.avi plays (from its 1st frame)

How would this work with the 'transparency' might be the next obstacle (hey - Michiel, wake up! I'm nearly done! ;-) )

Well, is something like this feasible?...

1. Scene allocates video.

2. Video play head is set to 0 seconds of its content and paused

3. *IF* content's value from xml file = CONTINUE, pause video at seconds of its content.

4. If transparency < 1 play video

Apologies for any presumptions made during this post Michiel. No videos were harmed during its making :)

"If possible it would be great if you could write an article about playing Flash video files inside BT."

I'd be honoured. though it would be a "For Dummies by a Dummy" version. Also need some time as under pressure with a product launch.

By the way, my first use of some simple BT'ing:
(Video 1)

It's what sparked the use of the dynamic content.

Thanks again for your time and fast responses, Michiel.


viddy, 12 years ago

[Sorry - seems the xml tags got zapped in the example. Hope you can see what I was getting at]

viddy, 12 years ago

Thanks for your ideas!

Once we have experimented with a VIDEO POSITION property. This allowed you to play the video in slow motion, super fast, pause it and even play it backwards. It worked and was terrific fun, but it was slow and playing it the normal speed was a bit of a problem :)

Technically it's all doable, but the challenge is to design a system/GUI that can handle all the different scenarios. We'll think about it!

michiel, 12 years ago

"but the challenge is to design a system/GUI that can handle all the different scenarios"

Maybe the challenge is to NOT handle all the different scenarios and concentrate on just the little things that make the greatest difference?

Adding video playback candy like is easily done in other apps before importing the video clips into BT. The main issue (for videos) is currently one of timing rather than fx, which ironically makes using dynamic content harder work than not using it at all (for video).

Plus, the timing issue is a much easier challenge to conquer, with much greater end benefits in relative terms: especially as it could be incorporated without effecting your GUI in any way.

Regardless, a truly fantastic app Michiel, and I look forward to seeing it evolve ever further.

Thanks again,

viddy, 12 years ago


I am wanting to do something similar to this.

The previous comments are from 2 years ago, so maybe the latest version has changed.

Is there anyway to control the position within the video as a video is brought into a show dynamically in the latest version?

IBMedia, 10 years ago

Video and audio files always start playing at the beginning of the show.

michiel, 10 years ago

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